Countdowns This Week (6pm Eastern)Sunday: 50 Years Of #1s (1970-2019)Monday: The Retro Top 40 - This Week In 1970Tuesday: The Retro Top 40 - This Week In 1980Wednesday: The Retro Top 40 - This Week In 1990Thursday: The Retro Top 40 - This Week In 2000Friday: The Retro Top 40 - This Week In 2010Saturday: The Billboard Hot 100